Sacramento officials announced Saturday they have reached a deal for the largest redevelopment project in city history – a $447.7 million arena at the Downtown Plaza, with up to 1.5 million square feet of offices, housing, stores and a high-rise hotel.

The public-private partnership agreement, announced in nine rapid-fire tweets by Mayor Kevin Johnson, puts the city on track to make a last-minute pitch to NBA officials in New York in two weeks to keep the Sacramento Kings from leaving town for Seattle.

It would require the city to commit $258 million in value, or 58 percent of the arena cost. Of that, $212 million would come from selling bonds backed by future revenues from city downtown parking garages. The city's contribution is the same as it was in last year's aborted project to build an arena at the downtown railyard.

The city also agreed to give the private development group the city's empty 100-acre plot next to Sleep Train Arena in North Natomas, as well as six other city properties, five of them adjacent to or near the downtown arena site. In total, the city properties have been valued at $38 million, according to city officials.

The agreement calls for the private development team to contribute $190 million to building the arena. That team is made of up investment billionaire Ron Burkle, 24 Hour Fitness founder Mark Mastrov and Vivek Ranadive, a Silicon Valley entrepreneur.

The city would own the arena; the private group would operate it and be responsible for its ongoing upkeep. The city would be guaranteed a minimum of $1 million in arena revenues annually, with bump-ups if arena revenues hit certain levels.

Representatives of the private group did not respond to The Bee's requests for comment Saturday evening.

Representatives of the private group did not respond to The Bee's requests for comment Saturday evening.

The complex deal, which sets a September 2016 date for opening the new arena, also involves a 5 percent surcharge on tickets for two years at Sleep Train Arena, and continuing for the 35-year term of the lease at the new arena.

An exact site for the new arena has not been determined. City officials say it should take up about two-thirds of the existing plaza site. They said they expect Macy's to remain.

City officials said they also agreed to give the developers the 3,700 city-owned parking spots beneath Downtown Plaza. About 1,000 of those will be demolished by construction. Once an arena is built, city officials say, the private group has indicated it needs to control the remaining 2,700 spots for premium parking at arena events, and for use with other development on the site.

The news of the deal broke just after 3 p.m. when the mayor hit the Twittersphere with a series of jubilant tweets, noting that the deal avoids new taxes, protects the city on an existing $70 million loan to the Kings and involves "no net impact on the general fund."

"I'm pumped!!" Johnson wrote. "Ron Burkle and I officially closed the deal a few minutes ago."

The 18-page preliminary term sheet is nonbinding. It was sent to City Council members Saturday afternoon and published on the city's website at 7:30 p.m.